Improvement in locks



llNirEn .STATES PATENT OFFIC.

ANSON HARDY, F. L. WALKER, AND G. A. WALKER, OF BOSTON, MASS.

,l M PROVEM ENT I'N LOCKS.

To all whom fit may concern.-

Beit known that we, ANSON HARDY, F. L. WALKER, and G. A. WALKER, all ofBoston, in the county of Suffolk and State of Massachusetts, haveinvented certain new and useful Improvements in Locks; and we doherebydeclare th at the following, taken in connection with the drawings whichaccompany and form part of this specification, is a description of ourinvention sufficient to enable thoseskilled in the art to practice it.

This invention relates to improvements in that class of locks employinga cylinder which can be turned in a ring by the key whenever theplungers, which work in both ring and cylinder, are properly placed,each of these plungers heingin two partsone in the cylinder and one inthe ring-so that the former cannot be turned in the latter, except whenthe abuttingjoint vof the two parts'of each of the plungers used is intheline ofthe joint between the cylinder and the ring. In such locks thekey-hole has heretofore been cylindrical, and the plungers have extendedinto the key-hole radially in direct lines or rangesthat is to say, thecenters of any one row of plun gers were all in one plane. The objectionto the cylindrical key-hole is that it affords facility for blowing thelock to pieces by powder, because it is easily tapped, so that aplug canbe screwed into the mouth of the key-hole, thus makin g a perfectpowder-chamber, which can be easily loaded and exploded.

Part of this invention consists in making the key-hole of such locks ashave been referred to and the key thereof in a thin rectangular form,which enables me to use a key of much less size and weight than the oldcylindrical one had, while the key-hole affords less room for a chargeof powder, and cannot be tapped out without being rst counterborcd.

Another part of this invention consists in the location or arrangementof the plun gers in key-holes of long and narrow formation in such locksas have been before generally referred to, they being placed out'of lineor Adirect range or in a zigzag manner, by which the key-hole is morefilled'up and obstructed, as to the operation of pick-locks, than itwould loe if the plungers were placed in range, and by which also a keycan be made with anges on alternate sides of the inclines, which operatethe plungers, this rendering it impossible Speciiication forming part ofLetters Patent No. 52,9975, dated March 6, 1&66; antedatcd February'ZB,1866 to take any single impression, which alone will form a guide fromwhich a false key can be made; and another part of this inventionconsists in the employment at the inner end of the key-hole, and beyondall ofthe plungers therein, of a safety check or slide arrangedto beoperated by the end of the key, and fitted so'closely as to preventenough rotationof the cylinder in the ring to cause the plungers to bindtherein, thus guarding the lock from indicative binding ofthe plungers,bywhichexperts have heretofore shown the old cylinder-andplunger lock tobe pickable.

Of the drawings, Figure l is an elevation of my improved lock, showingthe key-*hole side and the plunge-rs within the key-hole, the bolt beingrepresented as withdrawn or fully back. Fig. Z'shows a cross-sectionofthe lock, taken in the line z z through the key-hole, and showingthe'position of the plungers whenthe key is withdrawn, and thelocationof the slide at 'the rear of the key-hole. Fig. 3 shows-alongitudinal section through the lock on the line x w, Figs. l, 2, and5, showing the position of the parts of the lock with the holtdrawn'back, and especially showing the zigzag location of the plungers.Fi g. et is the section seen in Fig. 2 in all respects, except that thekey is shown in place, illustrating the position of the plungers when soplaced that the bolt can be thrown. Fig. 5 is an elevation of the lock,showing the side opposite that exhibited in Fig. 1,'part of thelock-case being broken away to disclose the check-slide, which is shownin the position it has when the bolt is thrown forward.

The key is shown in Fig. 4 and in the de tailed Views not numbered.

It will be seen that the thickness of the key is equal to the width ofthe key-hole, while the diameter of the plungers in the key-hole is lessthan its width. This permits the formation of flanges on one side ofeach incline of the key, by which the plungers are lifted, and as thezigzag arrangement of the plungers admits of the anges being on oppositesides of the key, it will appear that no single impression of the key inplastic material will give a correct model from which a burglar canconstruct a duplicate key.

a a are the plungers, which are formed with shoulders, to prevent themfrom dropping too far into the keyhole, these plun gers being free toslide in the cylinder b and to drive their counterparts a' ct in thering `c outward, so that when moved just the right amount, as by the keyof the lock, the joints between (t a and a a come just in the jointbetween b and c, and in this condition, when the bolt is back, there isnothing to prevent'rotation of the cylinder b, which carries the stud d,and this, working in a slot in the bolt e, throws it forward. j

The bolt e is fitted to slide closely across the inner end of thecylinder, and the relation of the stud d and the slot in the bolt inwhich the stud works is such that there is no communication from theinner end of the key-hole with The interior of the lock-case, by whichpowder could be introduced therein when the bolt is unlocked, as in Fig.3, or is locked or thrown forward, as in Fig. 5.

The position and relation of the stud d and its slot 'in the bolt withreference to the keyhole iscle'arly shown in Figs. 3 and 5.

The springsj'f serve to keep the plungers a a a apressed inward, and actin conjunction withthe key.

When the bolt is thrown forward the guides g g, in which the check-slideh 7L is fitted, assume the position` shown in Fig. 5, and when the-keyis withdrawn the spring t' forces 7L across the joint between thecylinder and the ring and forces hinto the key-hole, a small pin in theside ot' h/ preventing too great 4ran ge of inward motion to h'. Thereversed position of h and h when the bolt e is thrown back is shown inFig. 3, and in Fig. 4 may be seen inV dotted lines beyond the inner endof the key, when in place in the lock, the piece 7L, which, it will beevident, willwhen the bolt e is forward, be pushed outward by the endlot' the key till' the joint between It and h coincides with the jointbetween b and c.

The purpose of the check-slides, which, from its peculiar location,A canonly be reached with great difticulty by any instrument other than thekey, is to prevent all play of the cylinder, both rotative and lateral,or endwise, which otherwise might be had from misiitting the parts ofthe lock, or otherwise, and thus prevent or check all indicative bindingof the pluugers, rendering the lock secure against the methods hithertoemployed by experts in illustrating how locks embodying thecylinderand-plunger construction might be picked.

We claiml. The key constructed as described, viz: with its operativeportion of a thickness equal only to about the diameter of that partofthe plungers which enters the key-hole, plus the amount needed for aflange on either side, when provided with inclines on its edges, each ofwhich has a flange, said anges being part on one side and part on theother of each edge of the key.

2. In such a lock, provided with such akeyhole as described, thearrangement of the plungers so as to enter the key-hole in a zigzagmanner, substantially as and for the purpose specified.

3. In a lock with a cylinder, ring, and plungers, the employment or" thecheck-slide, when arranged at the inner end ot the key-hole, andoperating substantially as specified.

In witness whereof we have hereunto set our hands this 15th day of June,A. D. 1865.

ANsoN HARDY. FAL. WALKER. e. A. WALKER.

Witnesses:

J. B. CROSBY, F. GoULD.

